Alcohol and drugs
Your BAC is 0.10%. According to the handbook's glossary, what does that number mean?
- There are 0.10 grams of alcohol in every 100 milliliters of your blood. Correct answer
- There are 0.10 grams of alcohol in every liter of your blood.
- You have had 0.10 ounces of alcohol for each drink.
Why
BAC is a concentration, the amount of alcohol present in your bloodstream. The glossary pins down the unit with an example: 0.10% means 0.10 grams of alcohol in 100 milliliters of blood. Spreading the same 0.10 grams through a full liter would be ten times as much blood and a far weaker concentration, so the second answer describes a different number. A per-drink amount is not what BAC measures at all. For scale, 0.10% is above the 0.08% limit that applies to drivers over 21.
Where this comes from
California Driver's Handbook, June 2025 edition. The correct answer is There are 0.10 grams of alcohol in every 100 milliliters of your blood.
The rule behind this one
California alcohol and drug rules for drivers goes through the whole topic, with the page of the California Driver's Handbook behind every rule.
More on alcohol and drugs
- You are taking a jet ski out on a lake. What does California law say about drinking alcohol while you operate it?
- You are 19 and an officer has you take a preliminary alcohol screening (PAS). It shows a BAC of 0.05%. What may the officer do next?
- You are 19 years old. At what blood alcohol concentration (BAC) does it become illegal for you to drive in California?
- You are carrying a bottle of wine that has already been opened. Where may it legally ride in your car?